[mythtv-users] Fixing BBC HD AC3 for PS3 playback

Andre Newman mythtv-list at dinkum.org.uk
Fri Mar 27 12:43:56 UTC 2009


I've found a more MythTV friendly way to fix BBC HD recordings so they  
play properly on the PS3 but I'm not too hot on the scripting so it  
could use some input....

I have added a user job to search and replace on the recorded file and  
replace the wrong AC3 headers with the AC3 private data header that  
the PS3 is happy with. I'm using bbe which is packaged with Ubuntu and  
can handle binary replace on >2GB files, took a while to find  
something fast that could do this.

The job:
mv "%DIR%/%FILE%" "%DIR%/%FILE%.ts" ; bbe -e "s/\xFF 
\x00\x00\x01\xC0/\xFF\x00\x00\x01\xBD/" "%DIR%/%FILE%.ts" > "%DIR%/ 
%FILE%" ;

Before anyone tells me this a very crude way to fix the transport  
stream I know that already ;-) this works correctly on all the BBC HD  
recordings I have (~2TB worth) and produces the exact same file as the  
windows BBCHDFixer.exe I had been using. I'm working on a way to  
mislabel the audio description channel so the PS3 ignores it as I  
currently have to manually select the second audio stream on playback.

I'm leaving the unconverted version of the file around until I'm happy  
that the job runs reliably, which currently it doesn't! 90% of the  
time it's fine but 10% the job appears in the queue as completed but  
there's no .ts version of the file and no errors showing in the  
mythbackend.log I'm thinking that the job needs some better failure/  
completion signalling (some at all) but don't really know where to  
start in adding that.

I've wasted days trying to get ffmpeg or mencoder (latest svn of both)  
to remux the recordings but mencoder doesn't seem to like demuxing the  
BBC HD stream correctly and ffmpeg seems to generate a broken  
transport stream.
This is my best so far ffmpeg in case there is an ffmpeg guru around:

ffmpeg -i file.mpg -f mpegts -copyts -map 0.0:0.0 -map 0.3:0.1 -vcodec  
copy -acodec copy -fflags genpts outfile.mpg

This works in that it produces a transport stream with h264 video and  
one ac3 audio in sync which the PS3 plays but the video is jerking  
back and forth madly like some frames are in the wrong order, this  
seems to be a problem that many have experienced with ffmpeg transport  
streams and it's the same in mplayer, even vlc doesn't play it!

So any help with either method is much appreciated.

Andre


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